骨髓间充质干细胞促进大鼠IgA肾病修复

目的 观察骨髓间充质干细胞（MSC）对大鼠IgA肾病有无修复作用，并探讨其可能的机制。 方法 SD大鼠随机分为MSC注射组、生理盐水（NS）组及健康对照组。前两组以牛血清白蛋白(BSA)+葡萄球菌肠毒素B（SEB）＋皮下注射四氯化碳（CCl4）的改良法建立IgA肾病模型。体外连续培养SD大鼠MSC并通过流式细胞仪和成骨成脂细胞诱导分化鉴定MSC，用5-溴脱氧尿嘧啶核苷（BrdU）体外标记培养的MSC。移植后1周及4周分别观察3组的体质量、尿蛋白量（24 h）、肾功能、肾脏病理变化、IgA荧光沉积变化；ELISA法检测尿中的MCP-1、TGF-β1量；RT-PCR法检测肾组织中MCP-1、TGF-β1 mRNA的表达情况；免疫组化观察细胞因子及BrdU标记的MSC在肾组织中的分布情况。 结果 移植后1周，MSC组尿蛋白量（24 h）（36.86±4.78） mg，Scr（53.50± 6.28） μmol/L；NS组尿蛋白量（24 h）(66.98±5.86) mg，Scr (82.50±8.36) μmol/L，两组差异有统计学意义（均P < 0.05）；同时，MSC组MCP-1、TGF-β1在尿中的含量及肾脏中表达均显著低于NS组（均P < 0.05）。移植后4周，MSC组体质量、肾脏病理变化、IgA荧光沉积与NS组差异有统计学意义；MCP-1、TGF-β1在尿中的含量及肾脏中的表达与健康对照组差异无统计学意义。随时间延长，BrdU标记的MSC在肾组织中分布却逐渐减少。 结论 MSC输注可促进大鼠IgA肾病的修复，其作用机制可能并不完全是依赖于MSC的直接分化，而是通过调节肾组织中细胞因子的分泌和（或）其他的功能进行修复。

Bone marrow mesenchymal stem cells contribute to renal repair in IgA nephropathy rat

Objective To observe whether bone marrow mesenchymal stem cells (MSCs) can promote the repair of IgA nephropathy and to explore its possible mechanism. Methods Sprague-Dawley rats were randomly divided into three groups which were MSCs injection group, normal saline(NS) infusion group and healthy control group. IgA nephropathy model was established by the improving method with BSA +SEB +CCl4 in former two groups. MSCs of SD rats were continuously cultured in vitro and identified with specific surface antigens by flow cytometry and osteogenic and adipogenic differentiation. MSCs were labeled with bromodeoxyuridine (BrdU) in vitro before transplanted. At 1st and 4th week after MSCs injection, the changes of body weight, urine protein, renal function, histopathology and IgA immunofluorescence were observed. MCP-1, TGF-β1 in urine were detected by ELISA. The expression of MCP-1, TGF-β1 in kidney were examined by RT-PCR. The cytokines and BrdU labeled MSCs were detected by immunohistochemistry to observe the disposition in kidney. Results At the end of the first week of MSCs transplantation, MSCs group urine protein (36.86±4.78) mg/24 h, serum creatinine (53.50±6.28) μmol/L, and the NS group urine protein (66.98±5.86) mg/24 h, serum creatinine (82.50±8.36) μmol/L, the differences between two groups were significant (P<0.05). At the same time, the content of MCP-1, TGF-β1 in urine and expression in renal tissue of MSCs group were obviously less than those of NS group (P <0.05). At the end of the 4th week, the body weight, histopatholngy, IgA immunofluorescence of MSCs group were remarkably improved as compared with those of NS group. The content of MCP-1, TGF-β1 in urine and expression in renal tissue, and renal pathological change in MSCs group had no significant differences as compared with those of healthy control group. As the time passed, the disposition of BrdU-labeled MSCs in kidney was taper. Conclusions MSCs injection contributes to renal repair in rat IgA nephropathy. The mechanism may partly depend on adjusting the excretion of cytokines in renal microenvironment and/or other functions rather than completely depend on their differentiation to renal cells.